Italian translation and validation of fatigue symptoms and impacts questionnaire in relapsing multiple sclerosis (FSIQ-RMS)

Background: Fatigue is a disabling symptom of multiple sclerosis (MS) and impacts on daily life. The Fatigue Symptoms and Impacts Questionnaire-Relapsing Multiple Sclerosis (FSIQ-RMS) is a new 20-item tool that investigates the aspects of fatigue in MS. It concerns motor, cognitive, social, and emotional aspects of fatigue. We aim at validating the Italian version of FSIQ-RMS in an Italian population of MS patients and demonstrate its reliability and construct validity. Methods: We included patients with diagnosis of MS, age between 18 and 70 years with ability to participate in a 90-min interview. Each patient completed the Italian version of FSIQ-RMS and Fatigue Severity Scale (FSS) at the same time. Construct validity was explored by the exploratory factor analysis; reliability was assessed with Cronbach’s alpha; and test–retest stability was examined through intraclass correlation coefficient (ICC). Concurrent validity was calculated using Pearson’s correlation. Results: We enrolled 171 patients (126 female and 45 male), 83% with relapsing MS (RMS), and 17% with secondary progressive MS (SPMS). Italian FSIQ-RMS showed a Cronbach’s alpha of 0.92; ICC was 0.96. Pearson’s correlation coefficient between FSIQ-RMS and FSS total score was statistically significant (p < 0.01); FSIQ-RMS inversely correlated also with BMI and positively with EDSS. Conclusion: The Italian version of FSIQ-RMS has excellent psychometric properties and can be used in research and clinical setting to evaluate physical, cognitive, and social fatigue in both RMS and SPMS.